This invention relates to a diving helmet.
A known diving helmet comprises a head and a body contacting portion which are made of a heavy metal or synthetic resin with a relatively large thickness to act as diving weight. It comprises a transparent front window, and an air supply tube is connected to the back of the head.
When air is supplied into the helmet, air exhaust noise generates and vibrates in the small space of the helmet to place a diver in uncomfortable condition.
If an air inlet is formed at the back remote from diver's mouth, he will be worried about leakage of fresh air before breathing, if he is a beginner. Further it is necessary to supply fresh low-humidity air to the front window enough to take off mist formed by breathing.
According to the present invention, the above disadvantages will be solved.
According to the present invention, there is provided a diving helmet which comprises a head and a body-contacting portion made of regid material with relatively large thickness to act as weight, the head comprising a transparent front window, an air supply chamber connected with an air supply tube at the back of the helmet, and a plurality of air holes which allow the air supply chamber to communicate with the inside of the helmet, at least one of the air holes being extended close to the front window.
The air supplied into the helmet through the air supply tube is depressurized in the air supply chamber, from which it is fed into the helmet through the air holes. Thus, the exhaust velocity through the air holes becomes lower than that directly from the air supply tube, thereby turning down exhaust noise. The fresh air through the air hole is partially blown to the front window directly, thereby preventing the window from getting misted.